Process of oxidizing iso-borneol to camphor



thereof.

UNITED STATES PATENT OFFICE.

ROLAND L. ANDREAU, 0F WILMINGTON,

NEMOUBS AND COMPANY,

DELAWARE, ASSIGNOB TO B. I. DU PONT 9:: OF WILMINGTON, DELAWARE, ACORPORATION OF OXIIDIZING ISO-BORNEOL T0 GAMPHOR.

Patented July 20, 1920.

DELAWARE.

PROCESS OF 1,347,071. Specification of Letters Patent. No Drawing.Application flied November 12, 1917. Serial No. 201,676.

To all whom it may concern Be it known that I, ROLAND L. ANDREAU, of\Vilmington, in the county of New Castle, and in the State of Delaware,have invented a certain new and useful Improvement in Processes ofOxidising Iso-Iiorneol to Camphor. and do hereby declare that thefollowing is a full, clear, and exact description thereof.

My invention relates process designed for borneol into camphorparticularly to a transforming isoby the oxidation ofmy invention is toprovide a process of the above character in which iso-borneol is rapidlyand readily transformed into camphor without depending upon the presenceof a starter or catalytic agent, such as copper, sodium nitrite, starch,etc. Furthermore in my process mixed ni trio and sulfuric acids are usedand a nitric acid of a low strength is used.

A further object is to provide a process of this character which ischeaper and moripractical than previous processes of a similar nature.

A further object is of this character in which spontaneously at theordinary or a relatively low temperaturc,-that is to say, below 40 'hichproceeds smoothly and regu larly until. practically all of the nitricacid has been used up and only a trace thereof remains in the residualweak sulfuric acid with which it is mixed in carrying out the roccss,and in which the sulfuric acid may be readily recovered forconcentration and fortification for further use.

A further object is to use mined acids containing such a percentage ofwater as not to have the reaction proceed too violently.

While my inventlon is capable of being carried out in many differentways, for the purpose of illustration, I shall describe only one Way ofaccomplishing the same hereinafter.

For example, I may proceed as follows: A quantity of mixed nitric andsulfuric acids is made, containing the following proportions 5 9.kilograms of sulfuric acid, 66

The object to provide a process the reaction starts portion of 1%., and253 kilograms of nitric acid, 26 136., specific gravity 1.22 The mixedacid is introduced into a container, which may be provided with anydesired type of stirring device. Thereupon about 1 kilogram ofisoborneol is added to the mixed acid. Only a small amount of theiso-borncol is added in order to avoid having the reaction proceed tooviolently. If the reaction proceeds too violently the undesirableproducts, such as resinous compounds and camphoric acid will be formed,and the compounds will become subjected to such violent cbullition thatthey cannot be retained in the vessel. When the temperature has risen toabove 40 C. indicating that the reaction has begun, which will usuallybe after about 15 minutes, additional iso-borneol is added gradually,and with caution taking care that the temperature of the mass remainsbetween 35 and i0" C. during the reaction, continuing the addition untilthe entire amount of isoborneol added equals 154 kilograms. Thesupermitant liquid, which contains the cam phor in the form of a looseaddition compound with N 0 is then decanted and run into water, wherethe camphor precipitates as a solid, and is then washed, centrifuged,dried and purified. In this way a substan' tially theoretical yield isobtained.

While I have described my invention above in detail, I wish it to beunderstood that many changes may be made therein without departing fromthe spirit of my in vention.

I claim.

1. The process which comprises oxidizing iso-borneol into camphor by theapplication of mixed nitric and sulfuric acids.

2. The process which comprises oxidizing iso-borneol into camphor by thea plication of mixed nitric and sulfuric aci s in such proportions as tostart the reaction spontaneously.

3. The process which comprises oxidizing iso-borneol into camphor by theapplication of mixed nitric and sulfuric acids in the prosubstantially57% sulfuric acid 66 B. and 43% ni ric acid 26 B.

Al Thdprocess w ich comprises oxidizing iso-borueol into camphor by theappli ation of mixed nitric and sulfuric acids, the tempcrature duringat least the first part of the reaction being maintained at -10 (I orless.

5. The process uhich comprises oxidizing iso-horneol into camphor by theapplication of mixed nitric and sulfuric acids in such proportions as tostart the reaction spontancously, the temperature during at least thefirst part of the reaction being maintallied at about 4W or less.

(5. The process which comprises oxidizing iso-borneol into ramphor bythe application of mixed nitric and sulfuric acids in the proportion ofsubstantially 57in, sulfuric a id 66" B6. and 431, nitric acid 26 lid,the temperature during at least the first part of the reaction beingmainta ned at about in or less.

T. The process which comprises oxidizing iso-borncol into camphor by theapplication of mixed nitric and .--ulfuri a ids, the temperature duringat least the tint part of the reaction being maintained. at approximately 3-) t.

is. The process which coinprisw oxidizing isobormol into camphor by theapplication of mixed nitric and sulfuric acids in such proportions as tostart the reaction spontaneonsly, the temperature during at least thefirst part of the reaction being maintained at approximately 35 (F.

9. The process which comprises oxidizing iso-borneol into camphcr by theapplication of mixed nitric and sulliuric acids in the proportion ofsubstantially 57'}? sulfuric acid 66 Be. and 43V nitric acid 26" 1%..the temperature during at least the first part of the reaction beingmaintained at approximately 35 C.

10. The process which comprises oxidizing is0l)orneol into camphor bythe application of mixed nitric and sulfuric acids, the isoborneol beingadded to the mixed acid initially in a small quantity until the reactionis started, and thereafter adding further quantities gradually.

11. The process which comprises oxidiz ing iso-borncol into camphor bythe application of mixed nitric and sulfuric acids in such. propoi'tionsas to start the reaction spontaneously, the iso-borneol being added tothe mixed acid initially in a smalluantity until the reaction isstarted, and t erea fter adding further quantities gradually.

12. The process which comprises oxidizing isoborneol into camphor by theapplication of mixed nitric and sulfuric acids in the proportion ofsubstantially 57% sulfuric acid 66 B. and 43% nitric acid 26" 136., theiso-borneol being added to the mixed acid initially in a small quantityuntil the reaction is started, and thereafter adding further quantitiesgradually.

135. The process which comprises oxidiz- 66 big iso-horueol into cumphorby the application of mixed nitric and sulfuric acids, the temperatureat least during the first part of the reaction being maintained at 40"(I. or less. the iso-borncol being added to the mixed arid initially ina small quantity until the reaction is started, and thereafter addingfurther quantities gradually.

14. The process which comprises oxidiz ing iso-horncol into camphor hthe application of mixed nitric and sul uric acids in such proportionsas to start the reaction spontaneously, the temperature at least duringthe first part of the reaction being maiutained at 40 or less, theiso-horneol being added to the mixed acid initially in a small quantityuntil the reaction is started, and thereafter inlding further quantitiesgradually.

1.3. The process which comprises oxidizing isdhorneol into camphor bythe application of'mixcd nitric and sulfuric acids in the proportion ofsubstantially 57% sulfuric acid 66 B6. and 43% nitric acid 26 lie, thetemperature at least during the first part of the reaction beingmaintained at 40 C. or less, the iso-borneol being added to the mixedacid initially in a small quantity until the reaction is started, andthereafter adding further quantities gradually.

16. The process which com )rises oxidizing iso-borneol into camphor bythe application of mixed nitric and sulfuric acids, the temperatureduring at least the first part of the reaction being maintained atapproximately 35 C, the iso-borneol bein added to the mixed acidinitially in a. sma l quantity until the reaction is started, andthereafter adding further quantities gradually.

17. The process which comprises oxidizing iso-borneol into camphor bythe application of mixed nitric and sulfuric acids in such proportionsas to start the reaction spontaneously, the temperature during a. leastthe first part of the reaction being maintained at approximately 35 (3.,the isoborneol being added to the mixed acid initially in a smallquantity until the reaction is started, and thereafter adding furtherquantities gradually.

18. he, process which com )rises oxidiz ing iso-borneol into camphor bythe application of mixed nitric and sulfuric acids in the proportion ofsubstantially 57% sulfuric acid 66 B6. and 43% nitric acid 26 1313., thetemperature during at least the first part of the reaction beingmaintained at approximately'35" (l, the iso-borneol being added to themixed acid initially in a small quantity until the reaction is started,and thereafter adding further quantities gradually.

19. The process of oxidizing iso-borneol into camphor in such a manneras to avoid the production of resinous compounds which comprisesinducing a reaction between mixed nitrlc and sulfuric acids andiso-borneol under controlled temperature conditions.

20. The process of oxidizing iso-borneol into camphor which comprisesbringing together iao-borneol and mixed nitric and sulhave hereunto setm furic acids at such a rate as to avoid violent obullition. 10

In testimony that I claim the foregoing hand. ROL ND L. ANDREAU.Witnesses:

R. E. S'rmoumnn, WILLAKD T. WHITE.

